IP:

• Patents protect a new invention, in exchange for the public disclosure of the invention
  Do not guarantee usage, instead, they grant the right to deny others usage
   
• Trademarks allow a company to protect a brand (i.e., the hypothetical Mickey Mouse Plush Toy™)
   
• Copyright protects creative works, including music.
  This can include material that you put onto a web page, but you need to be the one who actually owns the copyright (which is different from merely possessing the material, or from)  in order to claim copyright.

The major point here is that you should be SURE that you're allowed to use something, before you incorporate it into your website. There are both ethical, legal ("Can someone sue you for using their work?") and technical ("What if someone changes their code, thus breaking your website?") issues.

ALSO, be sure to read through any Terms Of Service (or "About this website", etc, etc links) - Homestead.com owns your website, etc
 

Background (Main points):

Scripting languages are supposed to be easier & quicker than strongly-typed languages

• typically interpreted, not compiled
• job/Tool control language, rather than software dev
• "connecting diverse pre-existing components to accomplish a new related task" (from Wikipedia)
  • Shell scripting
  • Windows Scripting Host
  • GUI program scripting
• 'Rapid application development'
• Automatic memory management
• Perf. penalty (thus not applicable for really large tasks)
  • vs. the ever-expanding capabilities of our computers
• Intellectual property implications (unless you can compile/obsfucate it)

History:

• <Hardware / firmware>
• machine language
• assembly language
• FORTRAN, etc
  • Typing
• Procedural languages
• OOP

JavaScript

• Implementation of the ECMAScript standard
• Syntactically similar to, but fundamentally different from, Java
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Security concerns

From W3CSchools:

• JavaScript gives HTML designers a programming tool - HTML authors are normally not programmers, but JavaScript is a scripting language with a very simple syntax! Almost anyone can put small "snippets" of code into their HTML pages
• JavaScript can put dynamic text into an HTML page - A JavaScript statement like this: document.write("<h1>" + name + "</h1>") can write a variable text into an HTML page
• JavaScript can react to events - A JavaScript can be set to execute when something happens, like when a page has finished loading or when a user clicks on an HTML element
• JavaScript can read and write HTML elements - A JavaScript can read and change the content of an HTML element
• JavaScript can be used to validate data - A JavaScript can be used to validate form data before it is submitted to a server. This saves the server from extra processing
• JavaScript can be used to detect the visitor's browser - A JavaScript can be used to detect the visitor's browser, and - depending on the browser - load another page specifically designed for that browser
• JavaScript can be used to create cookies - A JavaScript can be used to store and retrieve information on the visitor's computer